Safety ski bindings

ABSTRACT

A safety ski binding particularly designed to hold the toe of a ski boot properly connected with a ski while automatically releasing the ski boot when required. The binding includes a pivot whose axis is perpendicular to the upper surface of the ski in at least one position of the pivot. A swing member is swingable about the pivot and carries a toe clamp for engaging the toe of a boot. A spring assembly coacts with the pivot and the swing member to yieldably resist swinging of the latter about the pivot axis from a central neutral position. The spring assembly acts in such a way as to increase the resistance to turning of the swing member from its neutral position only through a predetermined initial angular increment. When the swing member turns beyond the latter increment, the spring assembly does not provide any additional resistance to turning of the swing member.

United States Patent Forcht [54] SAFETY SKI BINDINGS 72 Inventor: Karl Dieter Fol-cm, Bad Schachenerstrasse 78, D- 8000 Munich 80, Germany [22] Filed: May 1, 1970 [21] Appl. No.: 33,779

[30] Foreign Application Priority Data May 6, 1969 Germany ..P 19 23 038.2

[52 US. Cl. "4280/1135 T [51] Int. Cl ..A63c 9/00 [58] Field of Search ..280/l 1.35 T

[56] References Cited I UNITED STATES PATENTS 3,455,570 7/1969 Salomon ..280/l 1.35 T 3,380,750 4/1968 Salomon ..280/l1.35 T 3,545,782 12/1970 Salomon ..280/11.35 T

FOREIGN PATENTS OR APPLICATIONS 1,562,027 4/1969 France 51 Sept. 26, 1972 Primary ExaminerBenjamin Hersh Assistant Examiner-Robert R. Song Attorney-Steinberg & Blake 57] ABSTRACT A safety ski binding particularly designed to hold the toe of a ski boot properly connected with a ski while automatically releasing the ski boot when required. The binding includes a pivot whose axis is perpendicular to the upper surface of the ski in at least one position of the pivot. A swing member is swingable about the pivot and carries a toe clamp for engaging the toe of a boot. A spring assembly coacts with the pivot and the swing member to yieldably resist swinging of the latter about the pivot axis from a central neutral position. The spring assembly acts in such a way as to increase the resistance to turning of the swing member from its neutral position only through a predetermined initial angular increment. When the swing member turns beyond the latter increment, the spring assembly does not provide any additional resistance to turning of the swing member.

9 Claims, 9 Drawing Figures PATENTED P I912 3.693, 989 SHEET 10F 4 IN V EN TOR.

PATENTEDSEP25 1912 SHEET 20F 4 I N V EN TOR.

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KAeA 0/5752 Poem/f BACKGROUND OF THE INVENTION The present invention relates to skiis.

ln particular, the present invention relates to safety bindings for skiis.

Thus, the present invention relates to'safety bindings to be used at the toe portion of a ski boot for holding the boot connected to the ski during normal operations while permitting the boot to free itself from the ski under conditions such as when the skier takes a fall.

Of course, there are at the present time, many different types of known safety devices. In connection with the holding of a toe portion of a boot on the ski, there are known safety devices which include, for example, a spring assembly composed of a horizontal sleeve extending longitudinally of the ski and having a compressed coil spring acting on a piston which is slidable in the sleeve. This construction is designed so that the piston rests on a piston seat with the spring opposing-swinging movement between the sleeve and piston seat. This construction is exemplified, for example, by the disclosure in the German Auslegeschrift 1,201,737.

This known construction for releasably clamping the toe portion of a boot to a ski brings about upon swinging between the sleeve and piston seat an opposing force which will return the front clamp back to its initial position for again receiving a ski boot after release of the ski boot upon swinging outwardly as, for example, in the case of a fall. However, this known construction has a serious disadvantage of opposing the swinging of the ski boot to its release position with a force which continuously increases as the extent of displacement of the ski boot from its initial position increases. Thus, the extent to which the coil spring is compressed so as to achieve the opposing force becomes increasingly greater with an increasing extent of swing of the clamp from its normal clamping position. In other words, the swinging of the ski boot until it is released by the front clamp requires a force which is at a maximum just before the actual release, since the greatest opposing moment is achieved with the compressed coil spring just prior to actual release of the boot.

This known construction results in the disadvantage of requiring in practice that the particular coil spring which is selected must fulfill two conflicting requirements. Thus, the coil spring must on one hand have a certain strength so that it is capable of reliably holding the boot properly connected with the ski during normal travel. in other words, the spring must not be so weak that it will permit the ski boot to shift laterally in its binding upon encountering relatively light impacts. Such an arrangement would result in a feeling of insecurity for the skier. On the other hand, it is essential that the force exerted by the spring be sufficiently small so that there will be no danger of reliable release of the boot during increasing opposing moments as the boot and its clamp swing from their normal position during encountering a fall, for example. In other words, the force of the spring must be sufficiently small to assure a reliable release of the ski boot before injury to the skier can occur. The fulfillment of both of these conflicting requirements has not yet been carried out in a satisfactory manner.

SUMMARY OF THE INVENTION It is a primary object of the present invention to provide a construction which will avoid the above drawbacks,

Thus, it is an object of the invention to provide a safety ski binding at the front, toe portion of a boot, capable of exerting sufiicient force to reliably maintain the boot in position upon encountering relatively weak forces, so that the ski boot will be reliably returned to its normal position in response to a small extent of turning of the ski boot and upon encountering insignificant tial increment so that the ski boot can be reliably released without any substantial resistance after turning through an initial predetermined increment. in this way, it will be possible to eliminate the disadvantage of providing a constantly increasing resistance to swinging of the ski boot and clamp from their normal positions.

It is a further object of the invention to provide a construction which can accomplish these objects while at the same time being composed of simple, rugged elements which are relatively inexpensive and which can be reliably and quickly assembled and disassembled.

Furthermore, it is an object of the invention to provide a construction which lends itself to a highly accurate adjustment of the operating forces, so that the structure of the invention can be readily adapted to the requirements of a particular skier.

Also, it is an object of the invention to provide a construction which lends itself to a ready combination with known elements such as releasable heel clamps.

Furthermore, it is an object of the present invention to provide a construction which can be combined with other structures such as structures for yieldably resisting forward movement of a ski boot.

According to the invention, the safety ski binding includes at the upper surface of a ski a pivot means which has a pivot axis extending perpendicularly with respect to the upper surface of the ski at least in one position of the pivot means. A swing member is supported by the pivot means for swinging movement about this pivot axis, and it is this swing member which carries the toe clamp which is adapted to engage the toe of vthe ski boot. A pair of spring means of the invention are symmetrically arranged with respect to the pivot axis and coact on the one hand with the pivot means and on the other hand with the swing member for yieldably resisting swinging movement of the latter beyond a central normal position. The spring means of the invention will provide an increasing resistance to swinging of the swing member beyond its normal central position only through a predetermined initial increment of swinging of the swing member beyond its initial normal position. When the swing member turns beyond this initial angular increment, the spring means of the invention provides no further resistance so that with the invention it is not required that the force resisting turning of the swing member to its release position constantly increase up to the instant of release of the ski boot.

3 BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is a perspective exploded illustration of one possible embodiment of a front safety ski binding of the invention illustrated on a fragmentarily shown ski;

FIG. 2 is a top plan view of the assembled front ski binding of FIG. 1 with part of the structure thereof shown in section in a plane parallel to the top surface of the fragmentarily illustrated ski;

FIG. 3 shows how the structure of FIG. 2 operates with the parts of FIG. 3 being shown in a position different from that of FIG. 2; 7

FIG. 4 is a sectional illustration at an enlarged scale, as compared to FIGS. 2 and 3, of a detail of the structure of FIGS. 2 and 3;

FIG. 5 is a transverse sectional elevation of another embodiment of a safety ski binding of the invention;

FIG. 6 is a top plan view of the structure of FIG. 5 partly in section and taken along line V V of FIG. 5 in the direction of the arrows;

FIG. 7 is a fragmentary sectional elevation showing a variation in a detail of the structure of FIGS. 5 and 6;

FIG. 8 is a fragmentary longitudinal sectional elevation of another embodiment of a structure for connecting the safety ski binding to a ski; and

FIG. 9 is a transverse sectional elevation taken along line VIII-VIII of FIG. 8 in the direction of the arrows.

DESCRIPTION OF PREFERRED EMBODIMENTS The embodiment of the front safety ski binding of the I invention which is illustrated in FIG. 1 includes a swing member 1 which is supported for swinging movement by a pivot means which is carried by the ski which is fragmentarily illustrated. The pivot means which supports the swing member for swinging movement includes a pivot pin 2 which in at least one position has a pivot axis which is perpendicular to the upper surface of the ski. The pivot pin 2 of the pivot means is formed with a pair of opposed flat parallel side surfaces 3 which define portions of a pair of opposed side recesses which are respectively directed toward the opposed longitudinal side edges of the ski. These flat side surfaces 3 are situated inwardly of the outer circumferential surface of the pin 2. The pair of flat side surfaces 3 are interconnected by circumferentially extending exterior surfaces of the pin 2 which form in section arcs of a circle. These circumferentially extending convexly curved surfaces interconnecting the flat surfaces 3 are also situated inwardly of the outer circumferential surfaces of the pin 2 above and below the flat surfaces 3. The transition from the flat surfaces 3 to the convexly curved interconnecting surfaces is somewhat rounded.

The swing member 1 has a pair of transversely extending bores or openings 4 and this swing member 1 is itself symmetrically situated on the pivot means formed by the pin 2.In the openings 4 are a pair of coil compression springs 5. These springs press at their inner ends against a pair of washers 6 which thus are pressed by the pair of springs 5 against the flat surfaces 3. At their outer ends, the pair of compression springs 5 compress against washers 7 which in turn press against adjusting screws 8. Thus, the assembly of springs 5 and washers 6 and 7 form a pair of spring means symmetrically arranged with respect to the pivot axis and coacting on the one hand with the pivot means and on the other hand with the swing member for resisting turning movement of the latter from its central normal position, as will be apparent from the description which follows. The screws 8 are threaded into the bores 4 and themselves have inner recesses receiving the washers 7. Both the washers 7 and the washers 6 have axially extending projections surrounded by the end convolutions of the coil springs.

In the illustrated example, each washer 6 is of a noncircular configuration at its outer periphery. Thus, each washer 6 is provided with a pair of opposed flat parallel surfaces 9 and 9' which extend parallel to the upper surface of the ski. The pin 2 is formed at the recesses thereof which are defined in part by the flat surfaces 3 with upper and lower flat guide surfaces also extending parallel to the upper surface of the ski and slidably engaging the surfaces 9 and 9'. Thus, with this construction while the washers 6 are capable of swinging with the swing member I about the pivot axis of the pivot 2, these washers 6 cannot turn about their own common axis which coincides with the horizontal axis of the swing member 1. Instead of a pair of flats 9 and 9 for each washer 6 it is possible to provide a single flat surface coacting with a corresponding flat surface of the pin 2.

As is best shown in FIG. 4, where only one of the washers 6 is illustrated, each washer has in engagement with the flat surface 3 of the pin 2 a pair of elongated flat end surface regions 10 and 10' which extend longitudinally perpendicularly with respect to the upper surface of the ski. Between these surfaces 10 and 10' of each washer which bear against a corresponding surface 3 of the pin 2, each washer is formed with a vertically extending groove 11 extending perpendicularly with respect to the upper surface of the ski throughout the entire height of the washer. Each groove 1 1 is substantially of a semicircular cross-section and has a radius which is smaller than the radius of the pin 2.

This particular configuration of each washer 6 is of an extremely great advantage. With this construction, upon swinging of the swing member 1 from its normal central position, the bearing surfaces 10 and 10' will coact with a corresponding surface 3 of the pin 2 in order to compress the coil spring 5 to achieve a turning moment opposing the turning of the swing member 1 from its normal central position and returning the swing member 1 back to its normal central position as long as the bearing surfaces 10 and 10' remain in engagement with the surface 3. On the other hand, upon swinging of the member 1 beyond the initial angular increment determined by the engagement of the surfaces 10 or 10' with the surface 3, the groove 11 enables the swing member 1 to turn all the way up to its position releasing the ski boot without any increase in the opposition to this turning once the surface 10 or 10' has moved beyond the surface 3. Thus, while there is a given initial increasing resistance to the turning of the swing member beyond its central normal position, this increasing resistance is maintained only for a predetermined initial angular increment after which there is no further increase in the resistance to turning of the swing member 1 all the way up to its boot-releasing position.

FIG. 3 schematically illustrates that position of the swing member which occurs just after the swing member has moved beyond the initial increment so that the grooves 11 permit the continued turning of the swing'member to its release position without any increased resistance. The toe clamp can be returned from its release position by hand again to its central normal position for receiving the boot.

In order to achieve as smooth and friction-free a functioning of the above structure as is possible, there is provided at the transition between the groove 11 and the surfaces and 10' as well as between the surfaces 10 and 10' and the outer periphery of the washer a rounded configuration.

With the embodiment of FIGS.13 the swing member 1 fixedly carries the front clamp 12 which engages the sole of the boot. This sole-engaging clamp member 12 has at its central region a pair of pointed projections 13 which become pressed into the front end surface of the sole of the ski boot and prevent an undesired lateral shifting of the boot. This front clamp 12 can be fixed to the swing member 1 by suitable screws, for example, and in this case the clamp 12 can be provided with elongated openings which will permit an elevational adjustment of the clamp so that it will become best adapted to the particular sole with which it is used.

With the embodiment of FIG. 1 the pivot means 2 is fixed to aplate element 14 which is hinged to a second plate 16 by way of a transversely extending hinge pin 15 providing for the plate 14 swinging movement about a transverse horizontal axis coinciding with the axis of the hinge pin 15. The plate 16 is fixed to the ski while the plate 14 is swingable about the pin 15 together with the pivot means 2.

This particular construction is particularly suitable for cross-country skiing, since the ski binding will, in

this case, permit through the plates 14 and 16 a relatively large extent of raising of the heel of the ski boot above the surface of the ski without limiting the extent of raising of the heel by the swing member 1 so that the swingable plate 14 and the ski boot can be swung about the pin 15 almost up to a position extending vertically orperpendicularly with respect to the upper surface of the ski.

Preferably the swingable plate 14 which carries the pivot means 2 is connected with the hinge pin 15 in such a way that when the plate 14 is parallel to the upper surface of the ski it is spaced from this upper surface by a distance corresponding to the thickness of a boot-engaging plate 18 which extends beneath and is connected with the swingable plate 14. At its rear heel region, the plate 18 may advantageously be provided with a conventional heel clamp which automatically engages and disengages with the heel of the boot, in a well-known manner. Thus, known devices are provided so that during downhill runs the boot-engaging plate 18 or the automatically releasable heel clamp are connected with the upper surface of the ski. However, during cross-country runs, the ski boot is held by the heel clamp only on the swingable plate 18 which is connected with the plate 14, so that an unhindered swinging movement of the ski boot about the axis of the hinge pin 15 longitudinally of the ski is possible to provide a natural ski operation in any direction, either up or down.

With the embodiment of the front clamp of the invention which is illustrated in FIG. 1, the sleeve portion 17 through which the hinge pin 15 extends forms part of the plate 16 which is fixed with the upper surface of the ski, the pivot 2 moving with respect to the sleeve 17 during swinging of the plate 14 about the hinge pin 15. It is also possible, of course, and often of advantage to make the central sleeve portion 17 part of the plate 14 so that in this case the pair of outer and sleeve portions through which the pin 15 extends would form part of the plate 16 rather than part of the plate 14. It is the former construction which is illustrated in FIG. 1. Thus, instead of the particular construction shown in FIG. 1 it is possible to provide the intermediate sleeve 17 as part of the plate 14 to swing together with the latter and the pin 2 and with respect to a pair of end sleeve portions which would in this case be connected with the plate 16 and would receive the opposed elongated end portions of the hinge 15. This latter construction is of a certain advantage because the pivot means 2 in this case could directly engage the intermediate sleeve 17 at all times, and since there would be no relative movement between the intermediate sleeve 17 and the pin 2, these components could, for example, be welded to each other. In any event, the intermediate sleeve portion and the pair of opposed sleeve portions through which the pin 15 extends can butt directly against each other, in end to end relation, as illustrated in FIG. 1. However, it is also possible to provide any desired spaces between the sleeve portions which receive the pin 15 with suitable spacer rings or collars situated between the sleeve portions which are spaced along the pin 15. Since it is important to the operation that the swinging movement of the plate 14 and pivot means 2, with the structure carried thereby, about the axis of the pin 15 take place with as little lateral play as possible, it is possible and advisable to surround the pin 15 within the sleeve portions which receive it with plastic intermediate sleeves. In other words, the pin 15 itself will be encased within a plastic sleeve which is in turn received within the sleeve portions illustrated in FIG. 1.

Referring now to the embodiment of the invention which is illustrated in FIGS.5 and 6, in this embodiment of a front ski clamp of the invention, the pivot means includes not only the pin 2 but also the elongated transversely extending body 21 which is rigid with the pin 2. This body 21 of the pivot means 2, 21 of this embodiment is formed symmetrically with respect to the pivot axis with a pair of vertically extending bores which receive the spring means which also includes in this embodiment the pair of coil springs 5. The pair of spring means of this embodiment include detent balls 22 against which the force of the springs 5 are directed through the intermediary of the washers which are sectionally shown in FIG. 5.

This embodiment of the invention includes a swing member 24 in the form of a simple plate formed with a central bore through which a circular portion of the pivot means extends so that the swing member 24 is supported also in this embodiment for free swinging movement about the axis defined by the pivot means. This swing member 24 is formed at an upper surface with a pair of spherical indentations 23 forming detent recesses for receiving the spring-pressed detent balls 22, respectively.

. The assembly-2, 21 may have a threaded connection between the components 2 and 21 thereof. Thus, in the example illustrated, above the intennediate' circular portion of the pin 2 which extends through the swing member 24, the pin 2 has a non-circular portion extending through a correspondingly shaped bore in the middle of the body 21. This body is formed with a recess receiving a nut which is threaded onto a threaded portion of small diameter of the pin 2 which extends into the recess which receives the nut. Inthis way, the body 21 is rigidly fixed with the pivot pin 2. However, it is also possible to form the components 2 and 21 from a single body of material so that the entire assembly is of a one-piece construction.

Just beneath the circular portion which extends through the swing member 24, the pivot 2 has an enlarged portion defining an upwardly directed shoulder 25 on which the swing member 24 rests. With this embodiment the toe clamp which directly engages the sole of the boot is fixed to the swing member 24, or it may be formed integrally therewith so as to provide also for this assembly a one-piece construction.

The spherical depressions 23 are of a radius which is greater than the radius of the spherical detent balls 22, as is clearly apparent from FIG. 5.

With both of the embodiments of the invention described above, the adjusting screws 8 form an adjusting means for adjusting the compression of the coil springs 5, and for this purpose the screws 8 have knurled peripheral edges to be grasped by the operator for turning the screws 8. Thus, by actuation of the adjusting means 8 it is possible to control the force which is required to release the safety clamp. It is preferred to provide atthe adjusting screw 8 and the structure which carries the same suitable marks such as an index and scale which enable a uniform adjustment of both of the adjusting screws 8 for individual front clamps.

In line with present-day developments, it is possible to provide at the head of the adjusting screw, in the direction of the thread, semicircular openings while providing the component which receives the adjusting screw 8 a bore in such a way that this latter bore threadedly carries a screw member the shank of which can simultaneously extend into one of the semicircular openings so as to prevent turning of the adjusting screw 8. In this way it is possible for the skilled mechanic initially to adjust the force required to release the clamp while avoiding any accidental or erroneous adjustment by the skier himself. The number of semi-circular recesses or openings which are to be provided for this purpose, will depend upon the desired fineness with which the adjustment is to be carried out.

It is also possible to prevent adjustment by the skier by utilizing, instead of a knurled adjusting screw an adjusting screw which requires a certain tool such as a screwdriver for the purpose of carrying out the adjustment, and at the same time threading such an adjusting screw always up to a given stop of the front clamp so that the extent of compression of each spring and thus the required release force can be regulated by providing between each coil spring 5 and its, adjusting screw a preselected number of washers in order to compensate for the extent which each spring 5 is compressed. In this way, after the skilled mechanic has adjusted the release force, an erroneous, unskilled adjustment, as by the skier himself, can be excluded.

FIG. 7 illustrates another embodiment of a detent recess for each detent ball 22. Thus, in this case, the swing member 24 will be formed, for each detent ball 22, with a depression which does not have the configuration of a relatively flat spherical depression, but instead has the configuration of a relatively narrow depression 26. With the detent recess 23 of the type shown in FIGS. 5 and 6 .or the detent recess 26 of the type shown in FIG. 7; there will be for a predetermined initial increment of turning of the swing member from its central neutral position a force or moment which is opposed to the turning of the swing member from its initial central position with the structure operating automatically to return the swing member to its neutral central position as long as the swinging movement does not go beyond the predetermined initial angular increment. However, once the extent of swinging has progressed beyond the predetermined initial angular increment, then with the embodiment of FIGS.5 and 6 when the swing member 24 has turned through an angle suffi cient to displace the spherical depressions 23 beyond the ball members 22, the latter will be engaged only by the flat horizontal upper surface of the swing member 24 so that there will be no further increase in the resistance to swinging of the swing member 24 and it can go to the release position without any further increase in the resisting force. With the embodiment of FIG. 7 after the swing member 24 has turned through an angle sufficient to displace the narrow recess 26 beyond each ball 22, there will be no continuously increasing opposing moment directed against the swinging of the member 24 and instead the safety clamp will swing to its release or open position without requiring any further overcoming of any additional force.

With the embodiment of FIGS.5 and 6 the pivot means 2, 21 is also fixed to the hinge plate 14 which swings about the hinge pin 15 with respect to the fixed plate 16 so that the front clamp of the invention is fixed to the swingable plate 14 by way of the pivot means 2, 21. As was the case with the embodiment of FIGS. 1-3, it is also possible with the embodiment of H655 and 6 to mount the pivot means 2, 21 directly on a plate which is fixed directly to the upper surface of the ski. With this latter construction a front clamp for downhill runs is provided while with the construction shown in FIGS.5 and 6 there is a front clamp which, as described above in connection with FIGS.13, in connection with the boot-engaging plate 18 and an automatically releasable heel clamp is particularly suitable for cross,- country travel. At the same time, it is possible to provide a completely useful downhill run type of binding which is completely practical if the releasable heel clamp and/or the boot-engaging plate 18 are fixed to the upper surface of the ski for the purpose of a downhill run.

It is to be noted that the combination of an automatically releasable heel clamp fixed to the plate 18 with a front toe clamp, such as that of the invention, which is swingable longitudinally of the ski where the boot-engaging plate 18 is fixed with the swingable component such as the plate 14 and where the structure includes devices for releasably connecting the plate 18 and/or the heel-clamp, when required, with the upper surface of the ski, are within the scope of the present invention.

With the embodiment of the invention which is illustrated in FIGS.8 and 9, the front clamp of the present invention is schematically represented by way of the pivot means 2, the adjusting screw means 8, and the front toe clamp component .12. This assembly is fixed,

by way of the pivot means 2, onto a longitudinally slidable unit 30 which forms a carriage which can be adjusted longitudinally of the ski. This carriage or longitudinally slidable member 30 is guided for sliding movement longitudinally of the ski by way of a suitable guide 31 which is fixed directly to the ski in the manner shown most clearly in FIG. 8. The free side edges of the guide member 31 surrounded by the portions of the slidable carriage 30 are clearly visible in FIG. 9.

With this embodiment, the pivot means 2 is directly fixed to a transverse member of the carriage 30. An elongated rod extends horizontally from the transverse member and is surrounded by a coil spring 32 which engages the rear end of an externally threaded member 33 which is freely turnable on the rod which extends through the spring 32. This rod extends between a pair of front and rear transverse members of ,the carriage 30, as is clear from FIG. 8. The exterior threads of the member 33 are received in the upper transverse grooves formed between the upwardly extending transverseprojections 34 of the guide 31. Thus, these upwardly extending projections 34 of the guide 31 will be received in the threads of member 33 so that when the latter is turned, the entire carriage 30 can be advanced longitudinally along the ski, thus adjusting the position of the entire pivot means 2 and all of the structure carried thereby longitudinally of the ski. It is to be noted that the rotary screw member 33 which is engaged by the front end of the spring 32 will thus have itsposition along the ski adjusted while at the same time the entire member 30 can be shifted forwardly in opposition to the spring 32. The adjustment by way of the member 33 thus serves only to adjust the longitudinal location of the pivot means 2. Thus, the position of the entire front clamp of the invention longitudinally of the ski can be adjusted in this way.

With this particular construction, it is possible to achieve an arrangement according to which the skier must shift .the entire front clamp forwardly, at least through a short distance in opposition to the spring 32, when the boot is initially joined with the front safety clamp of the invention. Therefore, with this construction, the ski boot has a certain amount of freedom of movement forwardly, which may be necessary, for example, in the case where the ski, during travel, is strongly pressed outwardly in the region of the ski binding in relation to the rest of the ski, as is, for example, the case when travelling through relatively short or narrow valleys or hollows. The capability of yieldable resilient movement of the clamp longitudinally of the ski is furthermore of advantage with respect to the release of the boot during a fall, since this possibility of the clamp to move forwardly as well as the possibility of lateral swinging movement enhances the capability of the boot to be releasedfrom the binding in an extremely effective manner when encountering unaccustomed drops. This construction of FIGS.8 and 9 is particularly of value since practically at every fall there is a for-ward component so that the possibility of moving the ski boot longitudinally of the ski is of value. This construction is of particular advantage with respect to ski bindings which have a heel holder which is shiftable longitudinally of the ski in opposition to a spring force, since during a fall there is generally no rearwardly directed component of force, so that this latter type of construction is of no particular effect and does not even come into play during a fall.

It is apparent from the above description of the invention that the person skilled in the art will have the possibility of carrying out various modifications without going beyond the invention. It is to be noted that various features referred to above can be used individually as well as in combination.

At the present time a preferred form of automatically releasable heel clamp to be used in combination with the front safety clamp of the invention is known in the trade under the name Nevada N17.

What is claimed is:

1. In a safety ski-binding a ski having an upper surface, pivot means defining a pivot axis which in at least one position of said pivot means extends perpendicularly with respect to said upper surface, a swing member carried by said pivot means for free swinging movement about said pivot axis, a toe clamp carried by said swing member for movement therewith and adapted to engage the toe of a ski boot for releasably clamping the latter to the ski, and a pair of spring means symmetrically arranged with respect to said pivot axis and operatively connected on the one hand to said pivot means and on the other hand to said swing member for yieldably resisting turning of said swing member and toe clamp therewith about said axis to a position releasing a ski boot, said pivot means including a pivot pin having a pair of opposed side surfaces, said swing member being swingable on said pin and having a pair of elongated openings extending transversely of the ski and communicating with said side surfaces of said pin, said spring means including a pair of coil springs respectively situated in said openings of said said member and a pair of washers respectively situated between said coil springs and said side surfaces of said pin, said washers being of a non-circular configuration, and said pin having recesses receiving said washers and preventing turning of the latter except about said pivot axis together with said swing member, circumferentially with respect to said pin.

2. The combination of claim 1 and wherein said recesses of said pin define a pair of flat, parallel opposed side surfaces against which said washers are pressed by said coil springs with said flat surfaces situated inwardly from the outer circumferential surface of said pin.

3. The combination 'of claim 2 and wherein said recesses of said pin include flat guide surfaces parallel to the upper surface of the ski and said washers respectively having corresponding flat surfaces parallel to the upper surface of the ski and engaging the guide'surfaces of the pin.

4. The combination of claim 3 and wherein each washer has a pair of opposed flat guide surfaces parallel to the upper surface of the ski and engaging corresponding surfaces of the pin.

5. The combination of claim 4 and wherein each washer has in engagement with a side surface of said pin a pair of fiat surfaces extending perpendicularly with respect to the upper surface of the ski and each washer being formed between the latter pair of fiat surfaces which are perpendicular to the upper surface of the ski with an elongated groove extending uniformly throughout the entire height of the washer perpendicularly to the upper surface of the ski.

6. The combination of claim 5 and-wherein each groove is of a semicircular configuration in cross-section.

7. The combination of claim 6 and wherein the radius of each groove is smaller than the radius of said 8. The combination of claim 7 and wherein the transition from the groove of each washer to the flat surfaces thereof between which the groove is situated and the transition from the flat side surfaces of the pin -to the circumferential exterior remaining surface thereof are rounded.

' 9. In a safety ski-binding, a ski having an upper surface, pivot means defining a pivot axis which in at least one position of said pivot means extends perpendicularly with respect to said upper surface, a swing member carried by said pivot means for free swinging movement about said pivot axis, a toe clamp carried by said swing member for movement therewith and adapted to engage the toe of a ski boot for releasably clamping the latter to the ski, and a pair of spring means symmetrically arranged with respect to said pivot axis and operatively connected on on the one hand to said pivot means and on the other hand to said swing member for yieldably resisting turning of said swing member and toe clamp therewith about said axis to a position releasing a ski boot, said pair of spring means coacting with said pivot means and swing member for increasing the resistance to turning of said swing member about said pivot axis from an initial neutral position only through a predetermined angular increment and for then providing no increase in resistance to turning of said swing member about said axis when said swing member turns beyond said initial increment of turning, a pair of plates being hinged to each other for swinging movement about an axis extending transversely of the ski, one of said plates being fixed to the ski and the other of said plates carrying said pivot means. 

1. In a safety ski-binding a ski having an upper surface, pivot means defining a pivot axis which in at least one position of said pivot means extends perpendicularly with respect to said upper surface, a swing member carried by said pivot means for free swinging movement about said pivot axis, a toe clamp carried by said swing member for movement therewith and adapted to engage the toe of a ski boot for releasably clamping the latter to the ski, and a pair of spring means symmetrically arranged with respect to said pivot axis and operatively connected on the one hand to said pivot means and on the other hand to said swing member for yieldably resisting turning of said swing member and toe clamp therewith about said axis to a position releasing a ski boot, said pivot means including a pivot pin having a pair of opposed side surfaces, said swing member being swingable on said pin and having a pair of elongated openings extending transversely of the ski and communicating with said side surfaces of said pin, said spring means including a pair of coil springs respectively situated in said openings of said said member and a pair of washers respectively situated between said coil springs and said side surfaces of said pin, said washers being of a noncircular configuration, and said pin having recesses receiving said washers and preventing turning of the latter except about said pivot axis together with said swing member, circumferentially with respect to said pin.
 2. The combination of claim 1 and wherein said recesses of said pin define a pair of flat, parallel opposed side surfaces against which said washers are pressed by said coil springs with said flat surfaces situated inwardly from the outer circumferential surface of said pin.
 3. The combination of claim 2 and wherein said recesses of said pin include flat guide surfaces parallel to the upper surface of the ski and said washers respectively having corresponding flat surfaces parallel to the upper surface of the ski and engaging the guide surfaces of the pin.
 4. The combination of claim 3 and wherein each washer has a pair of opposed flat guide surfaces parallel to the upper surface of the ski and engaging corresponding surfaces of the pin.
 5. The combination of claim 4 and wherein each washer has in engagement with a side surface of said pin a pair of flat surfaces extending perpendicularly with respect to the upper surface of the ski and each washer being formed between the latter pair of flat surfaces which are perpendicular to the upper surface of the ski with an elongated groove extending uniformly throughout the entire height of the washer perpendicularly to the upper surface of the ski.
 6. The combination of claim 5 and wherein each groove is of a semicircular configuration in cross-section.
 7. The combination of claim 6 and wherein the raDius of each groove is smaller than the radius of said pin.
 8. The combination of claim 7 and wherein the transition from the groove of each washer to the flat surfaces thereof between which the groove is situated and the transition from the flat side surfaces of the pin to the circumferential exterior remaining surface thereof are rounded.
 9. In a safety ski-binding, a ski having an upper surface, pivot means defining a pivot axis which in at least one position of said pivot means extends perpendicularly with respect to said upper surface, a swing member carried by said pivot means for free swinging movement about said pivot axis, a toe clamp carried by said swing member for movement therewith and adapted to engage the toe of a ski boot for releasably clamping the latter to the ski, and a pair of spring means symmetrically arranged with respect to said pivot axis and operatively connected on on the one hand to said pivot means and on the other hand to said swing member for yieldably resisting turning of said swing member and toe clamp therewith about said axis to a position releasing a ski boot, said pair of spring means coacting with said pivot means and swing member for increasing the resistance to turning of said swing member about said pivot axis from an initial neutral position only through a predetermined angular increment and for then providing no increase in resistance to turning of said swing member about said axis when said swing member turns beyond said initial increment of turning, a pair of plates being hinged to each other for swinging movement about an axis extending transversely of the ski, one of said plates being fixed to the ski and the other of said plates carrying said pivot means. 